The main structure of the projector nowadays includes an illumination system, a light valve, and a projection lens, wherein the illumination system is used to provide an illumination beam, and the light valve is used to convert the illumination beam into an image beam. The projection lens is used to project the image beam on the screen, so that the image is formed on the screen. In the illumination system of the projector, a plurality of lenses is usually disposed on the transmission path of the incident light to improve the efficiency of the incident light. Since the incident light is affected by the difference between the refractive index of different media and an incident angle, a part of the incident light is lost due to the phenomenon of total reflection.
In order to solve the above problems, the industry has utilized a variety of techniques for making microstructures on lenses to improve the lens anti-reflection effect. For example, Lithographie Galvanoformung Abformung (LIGA) or E-Beam is used to perform the mold processing of the microstructures. However, in addition to the high cost, the mold processing only can make the microstructures on a plane or a gentle curved surface. Therefore, a lens produced by the process has poor anti-reflection effect. How to overcome the said problems become the focus of the ordinary skilled in the art.